U.S. patent application number 13/184166 was filed with the patent office on 2012-01-26 for battery pack and method for controlling of charging and discharging of the same.
This patent application is currently assigned to SAMSUNG SDI CO., LTD.. Invention is credited to Young-Bok KIM.
Application Number | 20120021255 13/184166 |
Document ID | / |
Family ID | 45493875 |
Filed Date | 2012-01-26 |
United States Patent
Application |
20120021255 |
Kind Code |
A1 |
KIM; Young-Bok |
January 26, 2012 |
BATTERY PACK AND METHOD FOR CONTROLLING OF CHARGING AND DISCHARGING
OF THE SAME
Abstract
A battery pack capable of safely control charging and
discharging and a method of controlling this charging and
discharging. The battery pack includes a battery assembly at least
one battery cell, a protective circuit board electrically connected
to the battery assembly, and an outer terminal electrically
connecting the battery assembly to an external power supply or an
external load. The protective circuit board includes a charging and
discharging device charging and discharging the battery assembly, a
temperature device measuring the temperature of the battery
assembly; and a charging and discharging controller electrically
connected to the battery assembly, the charging and discharging
device, and the temperature device and controlling the charging and
discharging of the battery assembly. The temperature device is set
to measure the temperature of the battery assembly in the state in
which the charging and discharging of the battery assembly
stops.
Inventors: |
KIM; Young-Bok; (Yongin-si,
KR) |
Assignee: |
SAMSUNG SDI CO., LTD.
Yongin-si
KR
|
Family ID: |
45493875 |
Appl. No.: |
13/184166 |
Filed: |
July 15, 2011 |
Current U.S.
Class: |
429/7 ;
320/134 |
Current CPC
Class: |
H02J 7/0078 20130101;
H02J 7/00308 20200101; H02J 7/00302 20200101; H01M 10/441 20130101;
H01M 10/443 20130101; H01M 2200/10 20130101; H02J 7/0091 20130101;
H02J 7/00304 20200101; Y02E 60/10 20130101; H02H 1/00 20130101;
H02J 7/00714 20200101 |
Class at
Publication: |
429/7 ;
320/134 |
International
Class: |
H01M 10/44 20060101
H01M010/44; H02J 7/04 20060101 H02J007/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 23, 2010 |
KR |
10-2010-0071644 |
Claims
1. A battery pack, comprising: a battery assembly having at least
one battery cell; a protective circuit board electrically connected
to the battery assembly; and an outer terminal electrically
connecting the battery assembly to an external power supply or an
external load, wherein the protective circuit board includes: a
charging and discharging device charging and discharging the
battery assembly; a temperature device measuring the temperature of
the battery assembly; and a charging and discharging controller
electrically connected to the battery assembly, the charging and
discharging device, and the temperature device and controlling the
charging and discharging of the battery assembly; and the
temperature device is set to measure the temperature of the battery
assembly in the state in which the charging and discharging of the
battery assembly stop.
2. The battery pack of claim 1, wherein: the protective circuit
board further includes a switching device that is electrically
connected to the charging and discharging controller and controls
the electrical connection of the battery assembly and the outer
terminal.
3. The battery pack of claim 1, wherein: the protective circuit
board further includes a current measuring device that is
electrically connected to the charging and discharging controller,
and the current measuring device senses overcurrent or overvoltage
flowing in the battery assembly during the charging or discharging
of the battery assembly to transfer the stop signal of the charging
and discharging of the battery assembly to the switching device
through the charging and discharging controller.
4. The battery pack of claim 3, wherein: the current measuring
device is set to measure current flowing in the battery assembly in
the state in which the charging and discharging of the battery
assembly stops.
5. The battery pack of claim 4, wherein: the temperature device is
set to measure the temperature of the battery assembly when current
flowing in the battery assembly is reduced to the referenced value
or less in the state in which the charging and discharging of the
battery assembly stops.
6. The battery pack of claim 3, wherein: the protective circuit
board further includes a timer that is electrically connected to
the charging and discharging controller and measures the time when
the charging and discharging of the battery assembly stop by the
switching device.
7. The battery pack of claim 6, wherein: the temperature device is
set to measure the temperature of the battery assembly when a
predetermined time elapses after the charging and discharging of
the battery assembly stops.
8. The battery pack of claim 6, wherein: the current measuring
device is set to measure current flowing in the battery assembly
when the predetermined time elapses after the charging and
discharging of the battery assembly stop.
9. The battery pack of claim 8, wherein: the temperature device is
set to measure the temperature of the battery assembly when the
current flowing in the battery assembly is reduced to the reference
value or less in the state in which the charging and discharging of
the battery assembly stops.
10. A method for controlling charging and discharging of a battery
pack, comprising: measuring current of a battery assembly; stopping
the charging and discharging of the battery assembly by sensing
overcurrent or overvoltage of the battery assembly; measuring the
temperature of the battery assembly; and resuming the charging or
discharging of the battery assembly when the temperature of the
battery assembly is reduced to a reference value or less.
11. The method of claim 10, further comprising: measuring the
current flowing in the battery assembly after the charging and
discharging of the battery assembly stops, the measuring the
temperature of the battery assembly is performed after the charging
and discharging of the battery assembly stop and the current
flowing in the battery assembly is reduced to the reference value
or less.
12. The method of claim 10, wherein: the measuring the temperature
of the battery assembly is performed after the charging and
discharging of the battery assembly stop and the predetermined time
elapses.
13. The method of claim 12, further comprising: measuring current
flowing in the battery assembly after the predetermined time
elapses, and the measuring the temperature of the battery assembly
is performed after the predetermined time elapses and the current
flowing in the battery assembly is reduced to the reference value
or less.
14. The method of claim 10, wherein: the stopping of the charging
and discharging of the battery assembly and the resuming of the
charging or discharging uses a switching device electrically
connected to the battery assembly and the outer terminal.
15. A method for controlling charging and discharging of a battery
pack, comprising: measuring current of a battery assembly; stopping
the charging and discharging of the battery assembly upon sensing
overcurrent or overvoltage of the battery assembly; measuring the
temperature of the battery assembly; and resuming the charging or
discharging of the battery assembly when the current of the battery
assembly is reduced to a first reference value and the temperature
of the battery assembly is reduced to a second reference value,
wherein the first reference value is greater than or equal to zero
volts under all circumstances and the second reference value is
greater than zero degrees Kelvin under all circumstances.
16. The method of claim 15, further comprising: measuring the
current flowing in the battery assembly after the charging and
discharging of the battery assembly stops, the measuring the
temperature of the battery assembly is performed after the charging
and discharging of the battery assembly stop and the current
flowing in the battery assembly is reduced to the reference value
or less.
17. The method of claim 15, wherein: the measuring the temperature
of the battery assembly is performed after the charging and
discharging of the battery assembly stop and the predetermined time
elapses.
18. The method of claim 17, further comprising: measuring current
flowing in the battery assembly after the predetermined time
elapses, and the measuring the temperature of the battery assembly
is performed after the predetermined time elapses and the current
flowing in the battery assembly is reduced to the reference value
or less.
19. The method of claim 15, wherein: the stopping of the charging
and discharging of the battery assembly and the resuming of the
charging or discharging uses a switching device electrically
connected to the battery assembly and the outer terminal.
20. The battery pack of claim 1, wherein charging and discharging
of the battery assembly resumes when the temperature is about equal
to or less than 40.degree. C.
21. The battery pack of claim 9, wherein charging and discharging
of the battery assembly resumes when the reference value is about
equal to or less than 4.15V and the temperature is about equal to
or less than 40.degree. C.
Description
CLAIM OF PRIORITY
[0001] This application makes reference to, incorporates the same
herein, and claims all benefits accruing under 35 U.S.C. .sctn.119
from an application earlier filed in the Korean Intellectual
Property Office on Jul. 23, 2010 and there duly assigned Serial No.
10-2010-0071644.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The described technology relates generally to a battery
pack.
[0004] 2. Description of the Related Art
[0005] Unlike a primary battery, a rechargeable battery is a
battery capable of performing charging and discharging and can
repeat a charging process of converting external electrical energy
into chemical energy and storing it and a discharging process of
converting chemical energy into electrical energy and using it.
[0006] An example of a representative rechargeable battery may
include a nickel hydrogen battery, a nickel cadmium battery, a
lithium ion battery, a lithium polymer battery, or the like. A
low-capacity rechargeable battery has been prevalently used for a
portable small electronic device such as a mobile phone, a laptop
computer, and a camcorder and a large-capacity rechargeable battery
is used for a power supply for driving a motor such as a hybrid
vehicle, or the like and a battery for storing power.
[0007] In the fields closely connected with real life, as the use
of the rechargeable battery is increased, the rechargeable battery
with high safety and reliability is needed.
[0008] The above information disclosed in this Related Art section
is only for enhancement of understanding of the background of the
described technology and therefore it may contain information that
does not form the prior art that is already known in this country
to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
[0009] Aspects of the described technology has been made in an
effort to provide a battery pack having advantage of safely
resuming charging and discharging when the charging and the
discharging of the battery pack stop due to overvoltage or
overcurrent.
[0010] Further, aspects of the described technology has been made
in an effort to provide a method for controlling charging and
discharging of a battery pack.
[0011] An exemplary embodiment provides a battery pack, including:
a battery assembly having at least one battery cell; a protective
circuit board electrically connected to the battery assembly; and
an outer terminal electrically connecting the battery assembly to
an external power supply or an external load. The protective
circuit board may include: a charging and discharging device
charging and discharging the battery assembly; a temperature device
measuring the temperature of the battery assembly; and a charging
and discharging controller electrically connected to the battery
assembly, the charging and discharging device, and the temperature
device and controlling the charging and discharging of the battery
assembly. The temperature device may be set to measure the
temperature of the battery assembly in the state in which the
charging and discharging of the battery assembly stop.
[0012] The protective circuit board may further include a switching
device that is electrically connected to the charging and
discharging controller and controls the electrical connection of
the battery assembly and the outer terminal.
[0013] The protective circuit board may further include a current
measuring device that is electrically connected to the charging and
discharging controller. In this case, the current measuring device
may sense overcurrent or overvoltage flowing in the battery
assembly during the charging or discharging of the battery assembly
to transfer the stop signal of the charging and discharging of the
battery assembly to the switching device through the charging and
discharging controller.
[0014] The current measuring device may be set to measure current
flowing in the battery assembly in the state in which the charging
and discharging of the battery assembly stop.
[0015] The temperature device may be set to measure the temperature
of the battery assembly when current flowing in the battery
assembly is reduced to the referenced value or less in the state in
which the charging and discharging of the battery assembly
stops.
[0016] The protective circuit board may further include a timer
that is electrically connected to the charging and discharging
controller and measures the time when the charging and discharging
of the battery assembly stop by the switching device.
[0017] The temperature device may be set to measure the temperature
of the battery assembly when a predetermined time elapses after the
charging and discharging of the battery assembly stops.
[0018] The current measuring device may be set to measure current
flowing in the battery assembly when the predetermined time elapses
after the charging and discharging of the battery assembly
stop.
[0019] The temperature device may be set to measure the temperature
of the battery assembly when the current flowing in the battery
assembly is reduced to the reference value or less in the state in
which the charging and discharging of the battery assembly
stops.
[0020] Another exemplary embodiment provides a method for
controlling charging and discharging of a battery pack, including:
measuring current of a battery assembly; stopping the charging and
discharging of the battery assembly by sensing overcurrent or
overvoltage of the battery assembly; measuring the temperature of
the battery assembly; and resuming the charging or discharging of
the battery assembly when the temperature of the battery assembly
is reduced to a reference value or less.
[0021] The method for controlling charging and discharging of a
battery pack may further include measuring the current flowing in
the battery assembly after the charging and discharging of the
battery assembly stops, and the measuring the temperature of the
battery assembly may be performed after the charging and
discharging of the battery assembly stop and the current flowing in
the battery assembly is reduced to the reference value or less.
[0022] After the charging and discharging of the battery assembly
stop and the predetermined time elapses, the measuring the
temperature of the battery assembly may be performed.
[0023] The method for controlling charging and discharging of a
battery pack may further include measuring current flowing in the
battery assembly after the predetermined time elapses, and the
measuring the temperature of the battery assembly may be performed
after the predetermined time elapses and the current flowing in the
battery assembly is reduced to the reference value or less.
[0024] The stopping of the charging and discharging of the battery
assembly and the resuming of the charging or discharging may use a
switching device electrically connected to the battery assembly and
the outer terminal.
[0025] According to the exemplary embodiments, the battery assembly
can safely resume the charging or discharging of the battery pack
after the charging and discharging of the battery pack stop due to
the overvoltage or the overcurrent.
[0026] In particular, the present invention can promote safety in
resuming the charging or discharging of the battery pack even when
the battery cell of the battery pack is damaged due to the
overvoltage or the overcurrent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] A more complete appreciation of the invention, and many of
the attendant advantages thereof, will be readily apparent as the
same becomes better understood by reference to the following
detailed description when considered in conjunction with the
accompanying drawings in which like reference symbols indicate the
same or similar components, wherein:
[0028] FIG. 1 is a flowchart showing an algorithm of a method for
controlling charging and discharging of a battery pack according to
a first exemplary embodiment;
[0029] FIG. 2 is a block diagram schematically showing the battery
pack according to the first exemplary embodiment;
[0030] FIG. 3 is a flowchart showing an algorithm of a method for
controlling charging and discharging of a battery pack according to
a second exemplary embodiment;
[0031] FIG. 4 is a flowchart showing an algorithm of a method for
controlling charging and discharging of a battery pack according to
a third exemplary embodiment; and
[0032] FIG. 5 is a flowchart showing an algorithm of a method for
controlling charging and discharging of a battery pack according to
a fourth exemplary embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The present invention will be described more fully
hereinafter with reference to the accompanying drawings, in which
exemplary embodiments of the invention are shown. The drawings and
description are to be regarded as illustrative in nature and not
restrictive. Like reference numerals designate like elements
throughout the specification.
[0034] In the specification and the claims that follow, when it is
described that an element is "coupled" to another element, the
element may be "directly coupled" to the other element or
"electrically coupled" to the other element through a third
element.
[0035] Recognizing that sizes and thicknesses of constituent
members shown in the accompanying drawings are arbitrarily given
for better understanding and ease of description, the present
invention is not limited to the illustrated sizes and
thicknesses.
[0036] In the drawings, the thickness of layers, films, panels,
regions, etc., are exaggerated for clarity. Like reference numerals
designate like elements throughout the specification. It will be
understood that when an element such as a layer, film, region, or
substrate is referred to as being "on" another element, it can be
directly on the other element or intervening elements may also be
present. Alternatively, when an element is referred to as being
"directly on" another element, there are no intervening elements
present.
[0037] In order to clarify the present invention, elements
extrinsic to the description are omitted from the details of this
description, and like reference numerals refer to like elements
throughout the specification.
[0038] In several exemplary embodiments, constituent elements
having the same configuration are representatively described in a
first exemplary embodiment by using the same reference numeral and
only constituent elements other than the constituent elements
described in the first exemplary embodiment will be described in
other embodiments.
[0039] Rechargeable batteries may be used as a battery pack
including a battery assembly having at least one battery cell
according to the used purpose and usage and outer terminals capable
of connecting it to an external power supply or external loads.
Generally, the battery pack includes a protective apparatus that
prevents overvoltage from being applied to a rechargeable battery
or overcurrent from flowing thereto during the charging and
discharging process. For example, when voltage or current with a
predetermined value or more is sensed while the battery pack is
charged and discharged, it may further include a protective
circuit, or the like, that stops the charging and discharging.
[0040] As such, when the charging and discharging of the battery
pack stop due to the overvoltage or the overcurrent, etc., by the
protective circuit, etc., the charging or the discharging may be
resumed by predetermined conditions. However, when the battery cell
of the battery pack is damaged due to the overvoltage or
overcurrent, the temperature of the cell is increased due to the
internal chemical reaction, such that the battery pack may be in
danger when it is reused.
[0041] Therefore, in reusing the battery pack by resuming the
charging or discharging thereof, a need exists for a protective
unit for safely reusing the battery pack in consideration of
whether the battery cell is damaged or the damaged degree of the
battery cell.
[0042] FIG. 1 is a flowchart showing an algorithm of a method for
controlling charging and discharging of a battery pack according to
a first exemplary embodiment and FIG. 2 is a block diagram
schematically showing the battery pack according to the first
exemplary embodiment. Hereinafter, a battery pack and a method for
controlling charging and discharging thereof according to a first
exemplary embodiment will be described with reference to FIGS. 1
and 2.
[0043] Referring first to FIG. 1, a method for controlling charging
and discharging of a battery pack according to the first exemplary
embodiment includes sensing overvoltage or overcurrent (S110),
stopping charging and discharging (S120), measuring a temperature
of a battery cell in a battery assembly 10 (S130), determining
whether the temperature of the battery cell is reduced to a
reference value or less (S140), and if so, resuming the charging or
discharging (S150). That is, battery operation resumes when the
reference value to the temperature is about equal to or less than
40.degree. C.
[0044] That is, in the first exemplary embodiment, when the
charging and discharging of the battery pack stops due to the
overvoltage or overcurrent, the charging and discharging of the
battery pack is resumed based on whether the temperature of the
battery cell is sufficiently reduced to a reference value or less.
Therefore, when the battery cell is damaged due to overvoltage or
overcurrent, etc., the charging and discharging are resumed in
consideration of the case in which the temperature of the battery
cell may be increased due to internal chemical reaction, thereby
making it possible to more safely reuse the battery pack.
[0045] The battery pack according to the first exemplary embodiment
may include a battery assembly 10, a protective circuit board 20,
and outer terminals P+ and P-. Referring to FIG. 2, a configuration
of the battery pack and a method for controlling charging and
discharging thereof will be described in detail.
[0046] The battery assembly 10 may be formed to include at least
one battery cell capable of performing charging and discharging and
electrically connected to a protective circuit board 20 and an
outer terminal.
[0047] The outer terminal may include a positive terminal P+ and a
negative terminal P- and serves to connect it to the external power
supply or the external load during the charging and discharging of
the battery assembly 10. Generally, when the outer terminal is
connected to the external power supply, the charging of the battery
assembly 10 is made and when the outer terminal is connected to the
external load, the discharging of the battery assembly 10 is
made.
[0048] The protective circuit board 20 may include a charging and
discharging controller 30, a charging and discharging device 40, a
current measuring device 50, a switching device 60, and a
temperature device 70 and serves to stop the charging and
discharging when overvoltage is applied to the battery assembly 10
or overcurrent flows therein and to resume it.
[0049] The charging and discharging device 40 of the protective
circuit board 20 may be connected to the battery assembly 10 and
includes a charging field effect transistor (FET) 41 and a
discharging FET 42 and when the charging FET 41 is driven, the
charging is performed and when the discharging FET 42 is driven,
the discharging is performed. The charging and discharging device
40 may be connected to the charging and discharging controller 30
and any one of the charging FET 41 or the discharging FET 42 is
driven to perform the charging or discharging of the battery
assembly 10 by the control of the charging and discharging
controller 30.
[0050] The current measuring device 50 of the protective circuit
board 20 may include a sensor resistor and is connected to the
battery assembly 10 to sense current flowing in the battery
assembly 10. When overcurrent of a predetermined reference value or
more flowing in the battery assembly 10 through the current
measuring device 50 is sensed, the current measuring device 50
transfers the stop signals to the charging and discharging
controller 30 so that the charging and discharging of the battery
assembly 10 stop and transfers the stop signals to a switching
device 60 through the charging and discharging controller 30.
Meanwhile, instead of the current measuring device 50, the voltage
measuring device capable of measuring the voltage of the battery
assembly 10 may be formed and the current measuring device 50 may
be further formed with the voltage measuring device.
[0051] The switching device 60 of the protective circuit board 20
is a device that can control the turn-on and off of the electrical
connection between the battery assembly 10 and the outer terminal.
As described above, when the stop signal of the charging and
discharging are transferred through the charging and discharging
controller 30, the switching device 60 is turned-off and thus, the
connection between the battery assembly 10 and the outer power
supply or the outer load is blocked to stop the charging and
discharging of the battery assembly 10.
[0052] The temperature device 70 of the protective circuit board 20
may be connected to the battery assembly 10 to serve to stop the
charging and discharging of the battery assembly 10 and then
measure the temperature of the batter cell in the battery assembly
10. As described above, when the battery cell is damaged due to
overvoltage or overcurrent, the temperature of the battery cell may
be increased by the internal chemical reaction and when the
charging or discharging is made in the state in which the
temperature of the battery cell is increased, since danger such as
the deterioration or explosion, etc., of the battery pack may
occur, the charging or discharging is resumed only when the
temperature of the battery cell reduces to the reference value or
less. That is, the temperature sensor 70 continuously senses and
measures the temperature of the battery cell to transfer the resume
signal of the charging or discharging to the charging and
discharging controller 30 when the temperature of the battery cell
is reduced to the predetermined reference value or less in
consideration of safety. As described above, the resume signal of
the charging and discharging is transferred to the switching device
60 through the charging and discharging controller 30 and thus, the
charging or discharging is resumed by the connection of the battery
assembly 10 to the outer power supply or the outer load.
[0053] As such, the battery pack according to the first exemplary
embodiment may include the protective circuit board 20 having the
temperature sensor 70 to resume the charging and discharging only
when the temperature of the battery cell in the battery assembly 10
is reduced to the reference value or less, thereby making it
possible to secure the safety and reliability in reusing the
battery pack.
[0054] Another exemplary embodiment will be described with
reference to FIGS. 3 to 5. In this case, in each exemplary
embodiment, the description of the same components as the first
exemplary embodiment will be brief or omitted.
[0055] FIG. 3 is a flowchart showing an algorithm of a method for
controlling charging and discharging of a battery pack according to
a second exemplary embodiment.
[0056] Referring to FIG. 3, a method for controlling charging and
discharging of the battery pack according to the second exemplary
embodiment may include sensing overvoltage or overcurrent (S210),
stopping charging and discharging (S220), measuring a temperature
of a battery cell in a battery assembly (S240) after the
predetermined time elapses (S230), determining whether the
temperature of the battery cell is reduced to a reference value or
less (S250), and if so, resuming the charging or discharging
(S260). That is, battery operation resumes when the reference value
to the temperature is about equal to or less than 40.degree. C.
[0057] Comparing the second exemplary embodiment with the first
exemplary embodiment, the second exemplary embodiment is different
from the first exemplary embodiment in that the temperature of the
battery cell is measured after the charging and discharging of the
battery assembly stop and the predetermined time elapses. In this
case, the predetermined time is the predetermined time consumed to
reduce voltage or current to the predetermined level after the
charging and discharging stop when the overvoltage or the
overcurrent is sensed. That is, according to the second exemplary
embodiment, after voltage or current is reduced to a predetermined
level or less, the temperature of the battery cell is measured.
[0058] The configuration of the battery pack according to the
second exemplary embodiment further may form a timer in the
protective circuit board in the configuration of the battery pack
according to the first exemplary embodiment, thereby confirming
whether the predetermined time elapses. In detail, the additionally
formed timer may be connected to the charging and discharging
controller of the protective circuit board and transfers the
measuring signals to the charging and discharging controller to
measure the temperature of the battery cell of the battery assembly
by using the temperature device after the predetermined time
elapses from the instant where the switching device is
turned-off.
[0059] Therefore, after voltage or current is reduced to a
predetermined level or less, the charging or discharging is
resumed, thereby making it possible to more safely reuse the
battery pack. In addition, since the temperature of the battery
cell is measured using the temperature device after the charging
and discharging stop and the predetermined time elapses, there is
no need to operate the temperature device immediately after the
charging and discharging stop, thereby making it possible to more
efficiently perform the process of resuming the charging or
discharging of the battery pack.
[0060] FIG. 4 is a flowchart showing an algorithm of a method for
controlling charging and discharging of a battery pack according to
a third exemplary embodiment.
[0061] Referring to FIG. 4, a method for controlling charging and
discharging of the battery pack according to the third exemplary
embodiment includes sensing overvoltage or overcurrent (S310),
stopping charging and discharging (S320), measuring current of the
battery assembly (S330), determining whether current is reduced to
the reference value or less (S340), if so, measuring the
temperature of the battery cell of the battery assembly (S350),
determining whether the temperature of the battery cell is reduced
to the reference value or less (S360), and if so, resuming the
charging or discharging (S370).
[0062] However, the range of the voltage or current under which
battery operation stops or resumes may vary. For instance, when the
voltage of the battery is equal to or exceeds 4.25V, it will be
considered an overcharge. If the voltage is equal to or less than
4.15V, the battery operation will resume. Further, the battery
operation may stop when the charge or discharge current is 1
C-rate. Meanwhile, battery operation resumes when current in the
opposite direction is sensed.
[0063] Therefore, battery operation may resume when the voltage is
equal to or less than 4.15V and the temperature is equal to or less
than 40.degree. C. Further, battery operation may resume when the
current in the opposite direction is sensed and the temperature is
equal to or less than 40.degree. C.
[0064] Comparing the third exemplary embodiment with the first
exemplary embodiment, the third exemplary embodiment is different
from the first exemplary embodiment in that the temperature of the
battery cell is measured after the charging and discharging of the
battery assembly stop and the current is reduced to the reference
value or less. That is, according to the third exemplary
embodiment, even though the current flowing in the battery assembly
resumes the charging or discharging, the temperature of the battery
cell is measured after it is reduced to the safe level or less.
[0065] The battery pack according to the third exemplary embodiment
is similarly formed to the configuration of the battery pack
according to the first exemplary embodiment. However, the current
measuring device connected to the battery assembly senses
overcurrent to transfer the charging and discharging stop signals
to the charging and discharging controller. Thereafter, the current
measuring device continuously senses and measures the current of
the battery assembly. The current measuring device transfers the
measuring signals to the charging and discharging controller to
measure the temperature of the battery cell of the battery assembly
by using the temperature device when the current flowing in the
battery assembly is reduced to the predetermined level or less.
[0066] Therefore, after voltage or current is reduced to a
predetermined level or less, the charging or discharging is
resumed, thereby making it possible to more safely reuse the
battery pack. In addition, since the temperature of the battery
cell is measured using the temperature device after the charging
and discharging stop and the predetermined time elapses, there is
no need to operate the temperature device immediately after the
charging and discharging stop, thereby making it possible to more
efficiently perform the process of resuming the charging or
discharging of the battery pack.
[0067] FIG. 5 is a flowchart showing an algorithm of a method for
controlling charging and discharging of a battery pack according to
a fourth exemplary embodiment.
[0068] Referring to FIG. 5, a method for controlling charging and
discharging of the battery pack according to the fourth exemplary
embodiment includes sensing overvoltage or overcurrent (S410),
stopping charging and discharging (S420), measuring current of the
battery assembly (S440) after the predetermined time elapses
(S430), determining whether current is reduced to the reference
value or less (S450), if so, measuring the temperature of the
battery cell of the battery assembly (S460), determining whether
the temperature of the battery cell is reduced to the reference
value or less (S470), and if so, resuming the charging or
discharging (S480).
[0069] However, the range of the voltage or current under which
battery operation stops or resumes may vary. For instance, when the
voltage of the battery is equal to or exceeds 4.25V, it will be
considered an overcharge. If the voltage is equal to or less than
4.15V, the battery operation will resume. Further, the battery
operation may stop when the charge or discharge current is 1
C-rate. Meanwhile, battery operation resumes when current in the
opposite direction is sensed.
[0070] Therefore, battery operation may resume when the voltage is
equal to or less than 4.15V and the temperature is equal to or less
than 40.degree. C. Further, battery operation may resume when the
current in the opposite direction is sensed and the temperature is
equal to or less than 40.degree. C.
[0071] Comparing the fourth exemplary embodiment with the first
exemplary embodiment, the fourth exemplary embodiment is different
from the first exemplary embodiment in that the temperature of the
battery cell is measured after the charging and discharging of the
battery assembly stop, the predetermined time elapses, and current
is reduced to the reference value or less. In this case, the
predetermined time is the predetermined time consumed to reduce
voltage or current to the predetermined level after the charging
and discharging stop when the overvoltage or the overcurrent is
sensed.
[0072] The battery pack according to the fourth exemplary
embodiment is similarly formed to the configuration of the battery
pack according to the second exemplary embodiment.
[0073] That is, the configuration of the battery pack according to
the fourth exemplary embodiment further forms a timer in the
protective circuit board in the configuration of the battery pack
according to the first exemplary embodiment, thereby confirming
whether the predetermined time elapses.
[0074] Further, the current measuring device connected to the
battery assembly senses overcurrent to transfer the charging and
discharging stop signals to the charging and discharging
controller. Thereafter, the current measuring device continuously
senses and measures the current of the battery assembly, thereby
confirming whether the current flowing in the battery assembly is
reduced to the predetermined level or less. Therefore, when the
predetermined time elapses and the current flowing in the battery
assembly is reduced to the predetermined level or less after the
charging and discharging stop, the measuring signals are
transferred to the charging and discharging controller to measure
the temperature of the battery cell of the battery assembly by
using the temperature device.
[0075] Therefore, after voltage or current is reduced to a
predetermined level or less, the charging or discharging is
resumed, thereby making it possible to more safely reuse the
battery pack. In addition, since the current flowing in the battery
assembly and the temperature of the battery cell is measured using
the current measuring device and the temperature device,
respectively, after the charging and discharging stop and the
predetermined time elapses, there is no need to operate the current
measuring device and the temperature device immediately after the
charging and discharging stop, thereby making it possible to more
efficiently perform the process of resuming the charging or
discharging of the battery pack.
[0076] While this disclosure has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *